首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   148篇
  免费   14篇
儿科学   15篇
基础医学   10篇
口腔科学   3篇
临床医学   19篇
内科学   41篇
皮肤病学   2篇
神经病学   12篇
特种医学   1篇
外科学   15篇
预防医学   4篇
眼科学   11篇
药学   5篇
肿瘤学   24篇
  2021年   3篇
  2020年   2篇
  2019年   1篇
  2018年   1篇
  2016年   3篇
  2015年   4篇
  2014年   3篇
  2013年   7篇
  2012年   8篇
  2011年   9篇
  2010年   4篇
  2009年   5篇
  2008年   5篇
  2007年   2篇
  2006年   12篇
  2005年   8篇
  2004年   8篇
  2003年   9篇
  2002年   6篇
  2001年   4篇
  2000年   4篇
  1999年   6篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1994年   1篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1989年   3篇
  1988年   3篇
  1987年   6篇
  1986年   3篇
  1984年   3篇
  1982年   1篇
  1981年   1篇
  1980年   2篇
  1978年   1篇
  1976年   1篇
  1975年   3篇
  1973年   1篇
  1970年   4篇
  1969年   1篇
  1968年   2篇
  1967年   2篇
  1966年   1篇
排序方式: 共有162条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Children with Down syndrome (DS) have an increased risk for leukemia. The prognosis for DS acute myeloid leukemia (AML) is better than for non-DS AML, but the clinical outcome of DS acute lymphoblastic leukemia (ALL) is equal to that of non-DS ALL. Differences in prognosis may reflect differences in cellular drug resistance. In vitro drug resistance profiles were successfully investigated on leukemic cells from 13 patients with DS AML and 9 patients with DS ALL and were compared with reference data from 151 non-DS AML and 430 non-DS B-cell precursor (BCP) ALL. DS AML cells were significantly more sensitive to cytarabine (median, 12-fold), the anthracyclines (2-7-fold), mitoxantrone (9-fold), amsacrine (16-fold), etoposide (20-fold), 6-thioguanine (3-fold), busulfan (5-fold), vincristine (23-fold), and prednisolone (more than 1.1-fold), than non-DS AML cells. Compared with DS ALL, DS AML cells were significantly more sensitive to cytarabine only (21-fold). After short-term exposure to methotrexate, DS AML cells were 21-fold more resistant than non-DS AML cells, but no difference was observed after continuous exposure. DS ALL cells and non-DS BCP-ALL cells were equally sensitive to all drugs, including methotrexate. Normal peripheral blood mononuclear cells from DS and non-DS children without leukemia showed highly resistant drug profiles. It was concluded that the better prognosis of DS AML might, at least partially, be explained by a specific, relatively sensitive drug-resistance profile, reflecting the unique biology of this disease. (Blood. 2002;99:245-251)  相似文献   
6.
Follicular dendritic cell tumor (FDCT) is a rare tumor mainly located in laterocervical lymph nodes. We report one case of mediastinal FDCT associated with a history of bullous skin disease and clinically obvious immunosuppression. This tumor was characterized by heavy mast cell infiltration. Mast cells were in close relationship with tumor cells as demonstrated by ultrastructural examination and their presence are probably related with the strong expression of mast cell chemoattractants as fraktalkine and stromal cell-derived factor-1α by tumor cells. The long follow-up period of more than 17 years allowed to us assess the relatively indolent evolution of this tumor characterized by three slowly growing local recurrences without metastasis.  相似文献   
7.
The aim of this study was to investigate the safety of laser use under the dental microscope. Nd:YAG, Er:YAG and diode lasers were used. The end of the tips was positioned at a distance of 5 cm from the objective lens of a dental microscope. Each eye protector was made into a flat disc, which was fixed on the lens of the microscope. The filters were placed in front of the objective lens or behind the eye lens. Transmitted energy through the microscope with or without the filters was measured. No transmitted laser energy was detected when using matched eye protectors. Mismatched eye protectors were not effective for shutting out laser energy, especially for Nd:YAG and diode lasers. None or very little laser energy was detected through the microscope even without any laser filter. Matched filters shut out all laser energy irrespective of their positions.  相似文献   
8.
There are sandboxes in public elementary school playground areas in Brazil, which can be harmful to children. They are at risk of cutaneous and visceral larva migrans infection caused by Ancylostoma spp. and Toxocara spp., respectively. The study was designed to investigate contamination by Toxocara spp. and/or their eggs and Ancylostoma spp. larvae in sand samples collected from the schools' sandboxes. Five hundred and thirty-five sand samples from 28 public elementary schools were collected during summer and winter and analyzed by both Baerman's method and centrifugal flotation technique. Ancylostoma spp. larvae were found in 35.7% (10/28) schools in summer time and in 46.4% (13/28) schools in the winter time. Eggs of Toxocara spp. could not be recovered from the samples analyzed and eggs from Ancylostoma spp. were seen in 0.56% (3/535) of the samples.  相似文献   
9.
Three cases of painful ophthalmoplegia have been described in which symptoms suggesting a tumor of the orbit justified neuroradiological assessment. Phlebography in each case revealed stenosis of the superior ophthalmic vein in its third portion, and non-opicification of the cavernous sinus. Hirtz incidences revealed contralateral cavernous sinus opacification and venous drainage through the coronary sinus. These neuradiological findings helped to differentiate this syndrome from other affections which have similar signs and symptoms.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号